Failed to build GraphicsMagick

[rail5]

A linker error in building GraphicsMagick:

[build]       graphicsmagick          x86_64-w64-mingw32.static
I mad
Failed to build package graphicsmagick for target x86_64-w64-mingw32.static!
------------------------------------------------------------
/opt/mxe/usr/bin/x86_64-w64-mingw32.static-ld: /opt/mxe/tmp-tiff-x86_64-w64-mingw32.static/tiff-4.6.0/libtiff/tif_webp.c:295: undefined reference to `WebPIDecGetRGB'
/opt/mxe/usr/bin/x86_64-w64-mingw32.static-ld: /opt/mxe/tmp-tiff-x86_64-w64-mingw32.static/tiff-4.6.0/libtiff/tif_webp.c:326: undefined reference to `WebPIDelete'
/opt/mxe/usr/bin/x86_64-w64-mingw32.static-ld: /opt/mxe/tmp-tiff-x86_64-w64-mingw32.static/tiff-4.6.0/libtiff/tif_webp.c:256: undefined reference to `WebPINewDecoder'
collect2: error: ld returned 1 exit status
make[1]: *** [Makefile:903: build-only-graphicsmagick_x86_64-w64-mingw32.static] Error 1

It seems that it's not properly finding some libraries. Manually changing the LIBS line in graphicsmagick.mk fixed it for me:

LIBS="`'$(TARGET)-pkg-config' libtiff-4 --libs` /opt/mxe/usr/x86_64-w64-mingw32.static/lib/libtiff.a /opt/mxe/usr/x86_64-w64-mingw32.static/lib/libwebp.a /opt/mxe/usr/x86_64-w64-mingw32.static/lib/libsharpyuv.a" \